PRIZM in 1978 divided all Americans into forty demographic clusters by ZIP code

Evidence

Working with public census data, and the relatively new Zone Improvement Plan (ZIP) codes created by the Post Office, Robbin would produce his great masterpiece by 1978. He called it the “Potential Ratings in ZIP Markets” system, or PRIZM. PRIZM sorted the entire U.S. population into forty subnations, or “clusters,” each with a set of exact geographical locations. With PRIZM, a new reality revealed itself to Robbin: there was no United States, but forty distinctive nations all calling the same continent home. — Tim Wu, The Attention Merchants, 604

Categorization

• XREF: Connects to the broader history of market segmentation and the rise of algorithmic audience profiling that later lineages include Facebook’s and Google’s ad systems; also the geographic determinism echoes the ‘cluster’ logic of modern data brokerage. — connects to: PRIZM reimagined America as repeating lifestyle-neighborhood clusters rather than states — Tim Wu, The Attention Merchants, 608; ZIP-code clustering replaced single-variable demographics as the defining marketing category — Tim Wu, The Attention Merchants, 605

Broader Connections

• PRIZM reimagined America as repeating lifestyle-neighborhood clusters rather than states #expands (0.92) — Tim Wu, The Attention Merchants, 608
• ZIP-code clustering replaced single-variable demographics as the defining marketing category #expands (0.85) — Tim Wu, The Attention Merchants, 605